why not build/have a HACKINTOSH built for you?
windows-box running OSX. a friend of mine put one together running W7 dual booted with OSX, for about $2500, has 8 cores, 12gb of ram, (2) 300gb WD 10k rpm scratch drives, plenty of video card space, 750w power supply, in a sweet aluminum/black case(still trying to find the case online)
here it is...
the only downside
is though: YOU ARE THE TECH GUY. there isn't someone you can call .
but if I were you, I'd get a Mac Pro, and write it off. you can just get a bare-bones one with a kick-ass set of processors, and upgrade the HD's and memory from OWC(other world computing) for A LOT LESS $$$ than if you ordered it straight from Apple.
same friend's dad(who bought a mac pro 2 months ago=graphic designer), upgraded his 2gb of stock ram to 16gb for like $500, apple would have charged like $1100. you do the math, he put one of the 300gb Raptor drives HERE
if I had the money for a shiny new mac pro, I'd buy the bare bones one, with the best processor that fit my budget, and then waddle over to OWC and get my upgrade ram and get the HD's from Newegg. can save a LOT OF $$$$.